1. Technical Field
The present disclosure relates to an electrolytic capacitor including a conductive polymer layer (solid electrolyte layer), and an electrolytic capacitor production method.
2. Description of the Related Art
Along with digitalization of electronic devices, small-sized and large capacitance capacitors, which are used in the electronic devices, having low equivalent series resistance (ESR) in a high frequency range have been demanded.
Promising candidates as small-sized, large capacitance, and low ESR capacitors are electrolytic capacitors including as a cathode material a conductive polymer such as polypyrrole, polythiophene, polyfuran, or polyaniline. For example, an electrolytic capacitor including a dielectric layer-formed anode foil (anode body), and a conductive polymer layer (solid electrolyte layer) as a cathode material, which is provided on the anode foil, is proposed.
In WO 2013/094462, from the viewpoint of, for example, reducing the ESR, it is proposed that a conductive polymer layer be formed on an anode body having a dielectric layer with use of a conductive polymer dispersion, and then the conductive polymer layer-formed anode body be impregnated with a conductive auxiliary liquid containing an aromatic compound having, for example, a hydroxyl group and a carboxyl group.
In Unexamined Japanese Patent Publication No. 2006-287182, from the viewpoint of, for example, suppressing corrosion of a dielectric layer, reducing the ESR, and increasing the electrostatic capacity, it is proposed that a solid electrolyte layer be formed with use of a conductive polymer solution whose pH is adjusted to 3 to 13.